Key fob door entry issue
 

I've looked all over and have not found my exact problem. If this is a repost I apologize.
I have a 1994 Corvette Convertible 50000 miles always garaged. About a month or so ago the fob. Just stopped working. Replace the batteries still not working. Found an article about loose connections in the fob. Soldered everything and it started to work like new. About 2 weeks. Then totally stopped working until the day I dropped my keys when they hit the ground the door unlocked. Work good for a couple days. So I bought a ew fob. New fob programmed to the car perfectly. Work flawlessly for a couple days. it only works part time now. Battery in the fob checked out good. Acts like the car goes to sleep and isn't waking up with the FOB is close. Soon as I put the key in the door and turn to open the door will unlock everything is working again. It just seems to be after the car sets a little time.you run into the store and back out all seems to work ok. sometimes even overnight you walk out and the car will open. Any ideas would be appreciated.